openssl/crypto/comp/c_rle.c

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/objects.h>
#include <openssl/comp.h>
static int rle_compress_block(COMP_CTX *ctx, unsigned char *out,
unsigned int olen, unsigned char *in, unsigned int ilen);
static int rle_expand_block(COMP_CTX *ctx, unsigned char *out,
unsigned int olen, unsigned char *in, unsigned int ilen);
static COMP_METHOD rle_method={
NID_rle_compression,
LN_rle_compression,
NULL,
NULL,
rle_compress_block,
rle_expand_block,
NULL,
};
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COMP_METHOD *COMP_rle(void)
{
return(&rle_method);
}
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static int rle_compress_block(COMP_CTX *ctx, unsigned char *out,
unsigned int olen, unsigned char *in, unsigned int ilen)
{
/* int i; */
if (olen < (ilen+1))
{
/* ZZZZZZZZZZZZZZZZZZZZZZ */
return(-1);
}
*(out++)=0;
memcpy(out,in,ilen);
return(ilen+1);
}
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static int rle_expand_block(COMP_CTX *ctx, unsigned char *out,
unsigned int olen, unsigned char *in, unsigned int ilen)
{
int i;
if (olen < (ilen-1))
{
/* ZZZZZZZZZZZZZZZZZZZZZZ */
return(-1);
}
i= *(in++);
if (i == 0)
{
memcpy(out,in,ilen-1);
}
return(ilen-1);
}